It is well-known that fluid flow modification apparatus comprising openings, for example baffles, can be used to affect fluid flow, and in particular can modify flow of fluid through a conduit in which they are located. Such control of fluid flow has many applications, including for example ventilation and fluid mixing.
Similarly, fluid flow modification apparatus is often used to control fluid flow around bodies, such as fluid flow around aircraft, fluid flow around motor vehicles and fluid flow in mixing apparatus. Particular fluid flow characteristics that are often controlled by fluid flow modification apparatus include flow speed, flow direction, energy transfer and noise.
Many factors can be adjusted to affect fluid flow through openings and around fluid flow modification apparatus, including the geometry of the fluid flow path, the fluid properties, the surrounding temperature and the speed at which the fluid flows.
Examples of existing types of fluid flow modification apparatus are described in WO-A-2007/113335 and WO-A-2009/124939. Examples of fluid flow modification apparatus used in particular as part of wind turbine blades are disclosed in EP-A-1338793 and as part of aircraft wings in U.S. Pat. No. 5,088,665.